Photo monitoring apparatus with visual/audio alarm
US5530432A · kind A · utility
4Cited by
14References
2Claims
0Family size
Inventor
Key dates
| Filing date | Feb 3, 1995 |
| Grant date | Jun 25, 1996 |
| Priority date | — |
| Expiry date | Feb 3, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J1/0271
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A photo monitoring apparatus including a photoresistor, a series of shunt resistors, and a comparator IC, wherein the comparator IC provides an output signal to a LED and a diaphragm speaker, when the voltage from the shunt resistors drops below a pre-set reference voltage, causing the LED to give light and the diaphragm speaker to produce a warning sound. The shell of the photo monitoring apparatus is installed with a digital time display controlled by a time circuit to indicate time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.